For jewellery testing at SGI Institute we prefer that you provide gemstones in a loose unmounted state. Mounted coloured gemstones set in jewellery can be tested depending on the form of mounting. For analysis of colour grading of gemstones, they need to be presented loose. Diamonds cannot be graded in jewellery while mounted and therefore have to be unmounted for detailed analysis. Pearls can be tested mounted or  unmounted according to the setting.

Please contact us for further inquiries regarding the unmounting of gemstones before testing.